The image processing method and apparatus calculate and store gradients representing directions and intensities of a pixel of interest and its surrounding pixels from pixel values of the pixel of interest and its surrounding pixels of image composed of the color image signals that are to be subjected to image processing, calculate connectivity of the pixel of interest with its surrounding pixels from the directions of the stored gradients, calculate directivities of respective R, G and B of the pixel of interest by calculating gradients of respective R, G and B channels of the pixel of interest and decide whether the pixel of interest is an edge portion or not from the calculated connectivity and directivities of respective R, G and B to extract the edge portion. As a result, the method and the apparatus can raise extraction precision of the edge portion, accurately perform the edge portion extraction and increase image quality. Moreover, the method and apparatus calculate correction amounts of degree of sharpness enhancement and granularities of a plurality of the specified regions formed by dividing the image data based on the extraction result of the edge portion and correct the image data based on these correction amounts. Accordingly, careful and minute corrections of granularity and degree of sharpness enhancement can be performed on the image recorded in one frame.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An image processing apparatus for photoelectrically reading an image recorded on a film or a subject so as to obtain mage data which is subjected to specified image processing to produce output image data, comprising: granularity correction amount calculating means for calculating a correction amount of a granularity in each of a plurality of specified regions base on the density of a each of the plurality of specified regions, said plurality of specified regions being formed by dividing said image data; and granularity correction means for correcting the granularity of said image data based on the correction amount of each specified region calculated by said granularity correction amount calculating means.
2. The image processing apparatus according to claim 1 , wherein said granularity correction means corrects said image data as a whole by selecting an optimal value from among correction amounts calculated on respective specified regions.
3. The image processing apparatus according to claim 1 , wherein said granularity correction means corrects image data in each specified region based on the correction amount corresponding to the respective specified region.
4. The image processing apparatus according to claim 1 , wherein said granularity correction means corrects only the image data in a specified region placed at a predetermined position based on the correction amount calculated from the specified region at the predetermined position.
5. The image processing apparatus according to claim 1 , wherein said specified region is a region composed of one pixel.
6. The image processing apparatus according to claim 1 , further comprising main subject extraction means for extracting an occupied region of a main subject from said image data, wherein, as said specified region, said occupied region extracted by said main subject extraction means or the other region than said occupied region is selected.
7. The image processing apparatus according of claim 1 , wherein said specified region is a set of pixels having specified density obtained from a density cumulated histogram of said image data.
8. The image processing apparatus according to claim 1 , wherein said density is a relative density difference from a base density of a film applied.
9. The image processing apparatus according to claim 1 , further comprising film kind distinguishing means for distinguishing a film kind, wherein said granularity correction amount calculating means adjusts a reference value for calculating the correction amount in accordance with the film kind provided from said film kind distinguishing means.
10. The image processing apparatus according to claim 1 , further comprising: sharpness enhancement degree correction amount calculating means for calculating the correction amount of a degree of sharpness enhancement in each specified region based on whether the plurality of specified regions formed by dividing said image data include an edge portion or not; and sharpness enhancement degree correction means for correcting the degree of the sharpness enhancement of said image data based on the correction amount of each specified region calculated by said sharpness enhancement degree correction amount calculating means.
11. The image processing apparatus according to claim 1 , wherein said granularity correction amount calculating means further calculates the correction amount of the granularity in each specified region based on whether the plurality of the specified regions formed by dividing said image data include an edge portion or not.
12. The image processing apparatus for photoelectrically reading an image recorded on a film or a subject so as to obtain image data which is subjected to specified image processing to produce output image data, comprising: sharpness enhancement degree correction amount calculating means for calculating a correction amount of a degree of sharpness enhancement in each of a plurality of specified regions based on whether the plurality of specified regions include an edge portion or not, said plurality of specified regions being formed by dividing said image data; and sharpness enhancement degree correction means for correcting said degree of the sharpness enhancement of said image data based on the correction amount of each specified region calculated by said sharpness enhancement degre correction amount calculating means.
13. An image processing method for photoelectrically reading an image recorded on a film or a subject so as to obtain mage data which is subjected to specified image processing to produce output image data, comprising the step of: calculating at least one of a correction amount of a granularity in each of a plurality of specified regions based on the density of each the plurality of the specified regions, said plurality of specified regions being formed by dividing said image data, and a correction amount of a degree of a sharpness enhancement in each of the plurality of specified regions based on whether the plurality of the specified regions formed by-dividing said image data include an edge portion or not, wherein the granularity or the degree of the sharpness enhancement of said image data is corrected based on the calculated correction amount of each of the plurality of specified regions.
14. The image processing apparatus according to claim 13 , wherein said correction amount of the granularity in each of said specified regions is further calculated based on whether the plurality of the specified regions include the edge portion or not.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 10, 2002
February 24, 2004
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